Usually

A failed evaporator fan, coils frosted solid from a bad defrost circuit, or a burned-out start relay on the compressor. Power reaching the light tells me the outlet and control board are alive — the cooling side isn't.

I check first

Whether the compressor is actually running, then the frost pattern on the evaporator. Those two answers separate an inexpensive part from a dead sealed system.

Usually

A clogged defrost drain backing up beneath the crisper drawers, or a split water line to the ice maker. In the valley, hard water scale is behind both more often than not.

I check first

Where the water actually starts. Ice under the drawers points one direction; a wet patch at the back wall points to the supply line.

Usually

Restricted venting. The dryer heats fine but can't push moisture out, so it keeps recycling humid air. Less often, a failed heating element or a weak blower wheel.

I check first

Airflow at the exterior vent hood, then element resistance. Airflow is the answer far more often than the part is.

Usually

On electric dryers, a blown thermal fuse, an open heating element, or half the 240V circuit gone — a tripped leg at the breaker will still spin the drum. On gas, an igniter or gas valve coil at the end of its life.

I check first

Voltage at the outlet before anything else. It's free to check and occasionally means you never needed me.

Usually

Something lodged in the drain pump — coins, an underwire, a hair tie. Sometimes a kinked or clogged drain hose, occasionally a failed pump motor.

I check first

The pump filter and impeller. On front loaders that access panel sits behind the lower kick plate, and it's the first place anything travels to.

Usually

Worn suspension rods or shock absorbers letting the tub swing, or on a top loader, a failed bearing. Sometimes it's just legs that were never levelled after delivery.

I check first

Level and leg lock nuts, then tub travel by hand. Two minutes of checking rules out the free fix before I quote the expensive one.

Usually

A bake element with a break you can't see, a drifting temperature sensor, or a failed igniter on gas ranges. Uneven browning on its own often points to the sensor rather than the element.

I check first

Actual cavity temperature against what the display claims, then sensor resistance. The gap between those two numbers tells me most of the story.

Usually

A clogged filter and spray arms, a weak wash pump, or a failing soap dispenser latch. Valley hard water scales up spray arm jets faster than most people expect.

I check first

Spray arm rotation and jet flow, plus incoming water temperature. A dishwasher fed lukewarm water will never clean well no matter what parts go into it.